1. Field of the Invention
The invention relates to a remote sensing smoke detector suitable for use in a building with hollow walls or ceilings such as with an attic or suspended ceiling or an attached closet, garage, or storage area. A main alarm and power source unit is affixed on the interior surface of the wall or ceiling, jointly referred to as planes with a mast extending therefrom through an opening or passageway in the plane. The mast provides for positioning of a sensor suitable for providing a signal to the main alarm unit in the presence of combustion products in the space above or behind the plane.
The signal is then appropriately amplified and converted to a desired alarm providing audio or visual indications, or both.
The mounting mechanism for the alarm unit includes a seal which may be a ring of elastomeric or other resilient material which seals the opening or passageway from communication with the interior room of the building and diluting the smoke, thereby improving a flexibility in mounting, reducing drafts and inaccuracies during sensing through passage of combustion gases from one side of the plane to the other.
The tip of the mast remote from the alarm unit may be fitted with a penetrating bit enhancing ease of placement of the entire apparatus by its penetration of obstructions above, or behind, the plane such as insulation in loose, batt or paper bonded roll form. With suitable removable protection for the smoke entry ports of a sensor, the bit and mast structure may be adapted to completely penetrate the plane without need for further tools, particularly in the case of suspended ceiling boards.
2. Description of Related Art
Several patents differing in structure and approach from the instant invention address certain aspects of the problem of sensing the presence of combustion products in remote spaces. Powers U.S. Pat. No. 4,758,827 issued July 19, 1988 addresses the problem of determining the presence of combustion products in a duct using an externally mounted smoke detector. Powers uses entrance and exit ports from the duct to the smoke detector and returning to the duct in order to accomplish the goal.
Two patents show variations on electronic remote sensing. Martin U.S. Pat. No. 4,160,246 issued July 3, 1979 uses radio transmission having one detector/transmitter unit and a receiver/annunciator. Machen U.S. Pat. No. 4,305,069 uses a self-contained removable remote or "personal" unit which may be removed from a "sustainer" unit for carrying by a person into a building space.
Rice U.S. Pat. No. 4,319,234 issued March 9, 1982 deals with a portable smoke detector adapted for fitting over a door and having two sensors one on either side of the door as will be seen; this does not address a number of the concerns dealt with applicant's structure including penetration of the remote space, penetration of obstructions and false alarms.